In the Linux kernel, the following vulnerability has been resolved:
iio: gyro: bmg160: bail out when bandwidth/filter is not in table
bmg160_get_filter() walks bmg160_samp_freq_table[] looking for the entry
matching the bw_bits value read from the chip:
<pre>
for (i = 0; i < ARRAY_SIZE(bmg160_samp_freq_table); ++i) {
if (bmg160_samp_freq_table[i].bw_bits == bw_bits)
break;
}
*val = bmg160_samp_freq_table[i].filter;
</pre>
If no entry matches, i ends up equal to the array size and the next line
reads one slot past the end. bmg160_set_filter() has the same shape, driven
by 'val' instead of bw_bits.
smatch flags both:
drivers/iio/gyro/bmg160_core.c:204 bmg160_get_filter() error:
buffer overflow 'bmg160_samp_freq_table' 7 <= 7
drivers/iio/gyro/bmg160_core.c:222 bmg160_set_filter() error:
buffer overflow 'bmg160_samp_freq_table' 7 <= 7
Return -EINVAL when no entry matches.
The set_filter() path is reachable from userspace via the sysfs
in_anglvel_filter_low_pass_3db_frequency interface, so userspace can
trivially trigger the out-of-bounds read with a value that is not in
bmg160_samp_freq_table[].filter.